In recent years, a third-generation mobile communication system (3G) defined by Third Generation Partnership Project (3GPP), which is a standardized project, or a Long Term Evolution (LTE) system corresponding to a so-called 3.9-generation mobile communication system (3.9G) has been used as a mobile communication system. In the mobile communication system, services are provided to a mobile communication terminal through a mobile communication network. For example, the following Patent Literature 1 discloses a system which performs a charging process corresponding to the result of usage of the services provided through the mobile communication network.